Photothermographic film typically includes a base material, such as a polymer, coated on at least one side with an emulsion of heat sensitive materials. After the film has been imaged (i.e., subjected to photo-stimulation), the resulting latent image is developed through application of heat to the film so as to heat the film to a prescribed temperature for a prescribed time. This relationship between time and temperature is critical to achieving a high quality image.
As such, controlling heat transfer to the film during the development process is crucial. If heat transfer is not uniform during development, visual artifacts, such as non-uniform density and streaking, may occur. If heat is transferred too rapidly, the base material of some films may expand too quickly resulting in expansion wrinkles that can cause visual and physical artifacts in the developed film.
Likewise, once the film has been heated to make the latent image visible, it is important to cool the film in order to prevent overdevelopment of the image. In the same way it is critical to control the heating process, it is also important to control the cooling of the film. If the chemical reaction of the emulsion (i.e., image development) is not stopped in a uniform fashion, non-uniform density and streaking may occur. If the film is cooled too rapidly, the base material may contract too quickly resulting in contraction wrinkles that can cause visual and physical artifacts in the developed film.
Various cooling techniques have been developed and employed by thermal processors for cooling photothermographic film. One technique employs a cooling plate, wherein heat is transferred from the heated film to the cooling plate, which is cool relative to the film, by sliding the film across the plate. As “throughput” requirements of processors have increased, active cooling has been added by blowing air across the side of the plate opposite the side contacting the film to remove heat from the cooling plate to enable the film to be cooled more quickly.
While such a technique is effective at cooling the imaging media, sliding the film on the fixed cooling plate may scratch the emulsion, which is still soft from the elevated processing temperature. Additionally, a further increase in the throughput requires an increase in size (where space is typically limited) or an increase in the rate of cooling, which may result in wrinkling of the base material of the imaging media.
In light of the above, as the throughput requirements of processors continue to increase while the size of processors continue to decrease, it is evident that there is a need for a compact cooling section providing increased throughput while maintaining a high level of image quality.